Posted
by
kdawson
on Friday September 18, 2009 @09:15AM
from the general-products-hull dept.

An anonymous reader notes a CNN.com report on Nanocomp Technologies, the first in the world to make sheets of carbon nanotubes. "In April, [CEO] Lashmore had a mechanical multicaliber gun shoot bullets at different versions of his sheet, each less than a fifth of an inch thick. ... Army tests show the material works as well as Kevlar. The military also hopes to replace copper wiring in planes and satellites with highly conductive nanotubes, saving millions of dollars in fuel costs."

Anyone know what this is, and if it's anything more that a marketing superlative? The only Google hits for the phrase [google.com] are this story.

Sounds like marketing-speak for "gee-whiz super-powerful gun", though I suppose that it could be some arrangement of barrels that tests the stuff with various caliber rounds. I'm not sure why one would bother with such a thing.

Despite the fact that the.357 magnum fires both.357 and.38 "caliber" rounds, the reality is, it is not really multi-caliber..38 caliber is actually.357 caliber. The difference between the rounds is not the width of the bullet, it's the powder charge. The reason.38 is called.38 despite only being.357 inches wide, is because it is a throwback to older days when they measured the width of the shell casing instead of the width of the bullet.

All or most armor manufacturers use a table top mounted "test gun" that they can change out the barrel and receiver to fire different caliber to test the protective effectiveness of their product. I don't think anyone can buy one of these you have to get them specially built.

If you ever watch any History or Discovery channel show(s) about fire-arms chances are they show a few of these.

There are several rifles and pistols that can be changed to accept different barrels and actions into the receiver. These different parts shoot ammunition of different sizes.

I would assume this is a bench mounted receiver that can be triggered remotely. Kind of like the mythbuster's Curve a Bullet Robot. This is done to make each shot as mechanically similar as possible and without endangering a human shooter that shouldn't be on the range on an armor defelction test.

Oh yeah, not to reply to myself, but shortly after high school I did some patent drawings for a cylindrical weapons mount you could load into a 120mm smoothbore cannon and inside the mount you could configure a.308,.50 cal or 25mm match grade barrels attached to an trigger mechanism that could be activated remotely while loaded in the main cannon of an Abrams.

This was supposed to be used for training purposes using ammo already found in the US Armory stores.

Anyone know what this is, and if it's anything more that a marketing superlative?

I can only speculate what they really mean, but the Thompson Center Contender is a single shot firearm designed to allow replacement of the barrel with a new barrel in pretty much any calibre from.17 on up. Which means that one of them, with a suitable pile of barrels (conveniently, T-C manufactures barrels too) can fire pretty much any rifle, pistol, or shotgun round in creation.

In the 1980s I worked in advanced ceramic materials development for Corning. We were pitching insulating sleeves to be cast into cylinder heads. At a meeting with the Ford SVO engineering group, one of their engineers said "The first thing you hear about a new material is always the best thing you will hear about it. After that, the 'yeah, buts' begin." Yeah, but is it safe? Yeah, but is it affordable? Yeah, but will it conduct / dissipate heat? Yeah, but is it environmentally friendly? It takes time for systems to be redesigned around the special attributes of revolutionary materials.

Yeah, but won't the existing technology develop to do the same job faster and cheaper than this one can be got to market? That's why wood, ceramics, iron and cement are still the base materials of civilisation, rather than titanium, magnesium and carbon fiber.

The only industry I've ever heard of that being the case in is with Memory and IC substrates and logical design. Wood, ceramics, iron, and cement haven't "advanced", significantly to keep their lead over the others. The reason that titanium, magnesium, and carbon fiber haven't overtaken them yet is that we haven't, yet, developed a super-cheap production method for them (similar to the Bessemer process that allowed steel production to become cheap enough for it to over-take iron and the Faber process that

And to be fair, in some cases the new materials have taken over. Most passenger jet designs are switching to carbon fiber bodies; the cost is high, but the lighter material means that the you need far less fuel on every trip, eventually paying for itself. (Yes, the 787 is having problems in production, but I suspect that's more a matter of poor coordination than any intrinsic weakness in the material.) And the GP ignored plastics, which relatively recently displaced all sorts of time tested materials in the construction of all manner of products. Who's to say that we won't find a way to produce carbon nanotubes cheaply in the next few years?

The electrolytic production of aluminum is Hall-Heroult, I believe. There exists a titanium electrolysis system or two, but they're still patent-encumbered. (I've also heard people argue that it's the difficulty in working with titanium rather than the production costs that make it so expensive.)

Working raw titanium can be a pain. If you aren't careful, it will gall and go all lumpy.

It'll catch fire before it melts, unless it is in an inert gas environment. Far right on the periodic table inert, it'll burn in nitrogen.

On the plus side, you'll have lots of titanium oxide dust around. If you think FeO+Al is fun, try TiO+Al+Fluorite+Calcium Sulfate. It won't just burn through an engine block, it might keep going into the concrete @ 3800 F

Carbon nanotubes act a lot like asbestos in our lungs. We don't know that it is carcinogenic yet, but in the initial reaction that CNT causes in mouse lung tissue is the same sort of reaction that asbestos fibers cause. It's not surprising because CNT are so similar to asbestos fibers. They are nanoscale fibers, they are highly resistant to chemical degredate. So I think it would be safer to assume that it is a probably human carcinogen and behave like it is so that 20-40 years from now we don't have hu

A fifth of an inch thick? When I initially read "sheets of carbon nanotubes" I was envisioning something on the order of micrometers thick. I'm sure this is still progress, but the story isn't as exciting as I was initially expecting it to be.

A fifth of an inch thick? When I initially read "sheets of carbon nanotubes" I was envisioning something on the order of micrometers thick. I'm sure this is still progress, but the story isn't as exciting as I was initially expecting it to be.

I know basically nothing about armor and weapons and whatnot...

But, while 1/5" may not be as thin as you imagined, it may very well be thinner than what is currently required. How thick a sheet of kevlar is necessary to stop a bullet?

It doesn't list the calibers used in TFA, so hard to be a judge. I shoot 1/4" steel plates all day with a.223 without much damage to them - though a lot depends on the bullet type. Lead bullets will splash, lead-nose jacketed bullets will shatter, steel-core will damage or penetrate. Step up to a.308 and good ammo, you're going to need 1/2" or more to have a chance of stopping it.

A.50? The only time I've shot steel with a.50 BMG, it penetrated the 3/4" steel plates I had like they were paper.

If I had to guess, they're talking about handgun rounds, though - in which case, it sounds pretty equivalent to Kevlar. Kevlar isn't just a "sheet", though, as a single sheet is easy to penetrate - its more about the way they interlock when layered, causing the bullet to apply its force to a greater surface area before penetrating.

According to wikipedia the density of nanotube is not that much different from Kevlar. Kevlar ~1.4, nanotube ~1.3.

So where's the advantage over Kevlar? It could be that the ballistic performance is much better than Kevlar allowing you to make armor with less material but otherwise this isn't an obviously better material than Kevlar.

In ballistic applications Kevlar will probably continue to win based on cost.

As for structural uses, back in the annals of history aramid fiber (Kevlar) was thought to be the Nex

Um, the idea is lightweight armour that will still stop a round. A 6" steel plate would stop just about anything they can send your way, but you won't be very mobile. Kevlar is lightweight. Carbon nanotubes are even lighter, and apparently they have better force distributing abilities as well, so you also need less thickness.

"Ever since, it was presumed that any needle-like fibres around 20 micrometers long with an ability to persist in the body could have similarly dangerous effects. Donaldson and colleagues have now shown this holds true for carbon nanotubes."

These fibres are supposed to be 100 um long. That may make a difference. Also, they're all glued together rather well. It's certainly not a given that they're also toxic.

...founded Nanocomp in 2004. They developed a patent-pending system, controlled by a computer, that could produce large quantities of one-millimeter nanotubes. This was long enough to start making yarn and sheets.

So they are still making 1mm long fibers and sewing them together to make strands and sheets. I wonder how much stronger a continuous strand would be? It seems like there is a lot of potential to make these things even stronger.

Nanocomp Technologies announces that their new nanotube technology is being applied to solve the "Sheryl Crow one square of toilet paper" problem.http://news.bbc.co.uk/2/hi/entertainment/6583067.stm [bbc.co.uk]
Specifically, the technology is intended to address "those pesky occasions where two to three could be required".

That's an interesting question, but doesn't it apply to kevlar too? We've had kevlar vests for years, but no ammunition made of kevlar that I've heard of. Maybe the material isn't suitable to be shot out at high speeds/pressures?

Kevlar and carbon nano-tubes are not particularly dense. The ideal projectile material is extremely dense, its why lead and depleted uranium are often used instead (or in conjunction with) of hard brass or steel.

A few years back, the trend in armor-piercing rounds was the teflon-coated brass round [wikipedia.org]. They are now banned, though not for the Teflon coating (which wears off in the barrel or peels away in flight), but because of the hard cores.

For clarification, Teflon coating of projectiles is designed to reduce barrel wear, and has nothing to do with penetration.

Most ammo manufacturers now use molybdenum coatings - not sure if that is because it is more effective, or because of the dumb "Teflon-coated cop-killing bullets that go through a bullet-proof vest!" bullshit the Brady group shrieked about in the 90s. FWIW, most any rifle bullet will penetrate light armor, and there are several surplus rounds that can even penetrate level IIIa from a pistol - 7.62x25 Tokarev being the most popular, in the CZ-52.

Interesting anecdote: When I was in the service (Army Infantry), some of the older sargents got to talking about unusual ammunition that they'd used/tested/heard about. Depleted Uranium came up, because it was before the first Desert Storm and no one had used it before. The other one still hasn't been used that I know of. It was a hollow plastic nose & metal cup round filled with liquid teflon.

The story went that during Viet Nam, a sniper was sent to wound some particular General, not kill him. He wasn't the greatest strategist, so we knew how to handle him, and didn't want him dead, but for some upcoming engagement we wanted him on the sidelines, so he was marked for a wounding and not a dirt-nap. They sent the sniper out with these new liquid teflon rounds to try. Mistake. When the round hit the General in the shoulder, the liquid came out in strings and tore his whole arm and shoulder off, inducing massive shock and bleeding him out in seconds.

In the 1970's, Kopsch, Turcos and Ward produced their "KTW" handgun ammunition using steel cored bullets capable of great penetration. Following further experimentation, in 1981 they began producing bullets constructed primarily of brass. The hard brass bullets caused exceptional wear on handgun barrels, a problem combated by coating the bullets with Teflon. The Teflon coating did nothing to improve penetration, it simply reduced damage to the gun barrel.

If you are NOT a (FFL) licensee under the Gun Control Act (an individual)
It is: ok to OWN AP ammo
ok to SELL AP ammo
ok to BUY AP ammo
ok to SHOOT AP ammo
NOT ok to MAKE AP ammo (18 USC sec. 922(a)(7))
NOT ok to IMPORT AP ammo (18 USC sec. 922(a)(7))

The definition of AP ammo is at 18 USC sec. 921(a)(17):
"(B) The term `armor piercing ammunition' means-
(i) a projectile or projectile core which may be used in a handgun and
which is constructed entirely (excluding the presence of traces of other
substances) from one or a combination of tungsten alloys, steel, iron, brass,
bronze, beryllium copper, or depleted uranium; or[...]

The definition of AP ammo is at 18 USC sec. 921(a)(17): "(B) The term `armor piercing ammunition' means- (i) a projectile or projectile core which may be used in a handgun and which is constructed entirely (excluding the presence of traces of other substances) from one or a combination of tungsten alloys, steel, iron, brass, bronze, beryllium copper, or depleted uranium; or

(ii) a full jacketed projectile larger than.22 caliber designed and intended for use in a handgun and whose jacket has a weight of more than 25 percent of the total weight of the projectile.

It's important to note that this subsection relates ONLY to ammunition which can be loaded in handguns. There are few shops with CNC lathes which turn out solid brass bullets, supposedly of highly uniform density metal, which are sold to be hand loaded for long range shooters. Steel and tungsten core rifle ammo is commonly available--or at least it was before all the hoarding hullabaloo.

This is the reason why FN Herstal couldn't ship the 5.7x27mm cartridge with the SS190 Steel/Aluminum core bullet. It can be used both in their PS90 carbine and FiveSeven pistol. If they only marketed the carbine in the US, an argument could be made that they would be legally able to ship the SS190 ammo, as it isn't intended for handguns, and by definition isn't armor piercing ammo, per federal law.

Your probably thinking about WP [wikipedia.org], White Phosphorus. Technically it's a smoke/incendiary round and produces gruesome burns on flesh and re-ignites on contact with oxygen. The White Phosphorus will melt at 44 C so the rounds have to be stored vertically. When I got out shortly after Desert Storm, officially WP was being replaced with Red Phosphorus which has much better IR obscuring smoke, is easier to handle and less gruesome on personnel; WP was limited to existing stocks.

People also used leather as armor, but so far no one has dug up a leather sword. The physical properties of kevlar as used for armor are entirely different from the physical properties of a good bullet. Kevlar has very high tensile strength allowing it to spread the impact over a large area by deforming and pulling on all the threads around it. With a bullet, you want all the force located in one small, strong, pointy area for penetration; which is why armor penetrating rounds are jacketed or tipped in a metal much stronger than lead or copper(steel, tungsten, depleted uranium).

you want all the force located in one small, strong, pointy area for penetration; which is why armor penetrating rounds are jacketed or tipped in a metal much stronger than lead or copper(steel, tungsten, depleted uranium).

Actually, the advantage of DU [wikipedia.org] isn't its strength but its density:

Depleted uranium is very dense; at 19050 kg/m^3, it is 1.67 times as dense as lead, only slightly less dense than tungsten and gold, and 84% as dense as osmium or iridium, which are the densest known substances under standard (i.e., Earth-surface) pressures. Thus a given mass of it has a smaller diameter than an equivalent lead projectile, with less aerodynamic drag and deeper penetration due to a higher pressure at point of impact.

I missed that lesson in history class. The one where the Roman Legions are beset by the whip-wielding Visigoth horde. On a side note, I'm pretty sure whips are only effective against Dracula and Nazis.

If artillery has problems getting through carbon nanotubes, oxyaluminum nitride, and spinel, how long until the artillery itself is made of those materials?

So, are you saying that whips were created to get through leather armor? If so, I think you need some sort of cite. If not, it is best if you take the post in context of what was said in the previous post (and before that and before that all the way up to OP). That the board is set up where you reply to comments. So that you don't have to explicitly say what the entire context of your statement is.

TFA doesn't say that it will stop artillery. It says they fired a "mechanical multicaliber gun" at 1,400 feet per second. It doesn't say what calibers or bullet weights they were using but the speed of 1,400 fps suggests that they are testing it against handgun equivalents. There are many off the shelf rifle calibers that will easily achieve twice that velocity. It would be interesting to see if this material is proof against them or if it's only useful against handguns.

Lightweight and hard (not necessarily strong) are not necessarily what you want in a bullet. Hard bullets destroy the rifling in the weapon. There are smoothbore guns, but not too many. Lightweight bullets don't retain their energy well over time.

The trend in artillery is for really heavy rounds, like Depleted Uranium or thin Tugsten spikes launched inside of a Sabot. If anything came from this in a prjectile I assume it would come from the Silver Bullet style like the high speed tugsten spike.

In that case we should try to make armor out of Jello. That way we trick them into trying to attack us with Jello instead of bullets. Not to mention the mass of new recruits we'll get when people hear they get paid to be in a giant Jello fight.

The only reason for using these exotic materials is that steel is just too heavy. Otherwise we could build body armour that looks like what was worn in Medieval Europe, but is around 3/4 of an inch thick. The problem is not many people can walk in a 400 Lb vest or a 150 Lb Helmet

That light weight which makes them superior for mobile armor (Fixed bunkers are still mostly just Iron blends and rock) makes them less effective as projectiles If you wan

Not that I'm defending wasteful military spending, but the reason they want this is not so much for the dollar savings on fuel, but for the logistical advantages of needing less fuel: extended range of existing aircraft, reduced need for aerial refueling, more sorties on the same fuel budget, etc.

The problem isn't the cost of the fuel, it's the cost and lost opportunities from the long supply train. Most non-lopsided battles aren't determined by who has the better equipment or even the better soldiers but by who has the better quartermaster.

The fuel cost savings comes in the form of weight. Copper is likely a lot heavier than the carbon nanotube material. Less weight, less fuel to keep the plane aloft. Alternatively, they could use it for carrying heavier payloads.

There is very little energy wasted in copper wiring, especially in airplanes! Moving to a material of higher conductivity will result in minuscule savings, and will be nowhere remotely close to covering the cost of the (extremely expensive) materials.

They aren't going to save fuel because it is more conductive. They aren't burning tons of fuel because of transmission losses from one end of the plane to the other.

They are going to save fuel because the nanotube wires will be lighter than the copper wires we use now. Less weight == less fuel.

But I dare say that military perspective is not on saving fuel costs. After all, why save money by putting in a smaller fuel tank when you can keep it the same size and use the fuel savings to fly further/faster?

It equals out to the same thing.

If you need to drop a bomb on someone 100 miles away, right now it costs you $100 in fuel to do it. If you replace all your copper with nanotubes and make the plane lighter you can do it for $90 in fuel.

If you need to drop a bomb on someone 110 miles away, right now it'll cost you $110 and you'll have to refuel somewhere along the line. Make the plane lighter with nanotubes and now you can do it for $100 in fuel and no refueling along the way.

It's not about resistive losses. It's about weight. Also carbon nanotubes haven't benefited from any economy of scale efficiencies, and hence the cost is likely to be much less once they are able to be manufactured in quantity. It's not like carbon is a rare material.

A 747 has approximately 190,000 feet of copper wiring - per this [copperinfo.com]. I would imagine that that translates to quite a bit of weight - if that weight were to be reduced significantly (by half or better) - the fuel savings would not be negligible. The other place suggested for their usage was in satellites - which is a market where the cost is per kilogram - and satellites, as they are now, I'm sure owe quite a bit of their weight to the wiring that makes them function.

They also claim it has other benefits, such as not having to worry about wires snapping and redundancy. I'd still feel a bit weird flying in a plane with no physical connection to the engines/wings/other.

it's probably the strength, using copper in air-frames pulling 10 G's is challenging, carbon-NT could hold up under 100's of G's such as guided artillery rounds [wikipedia.org] or missiles that would turn a human pilot into jelly.

He was able to move in it, but not very well. If it were combined with some of the powered exo-skeletons out right now it would, probably, be what you're talking about. Of course, the weave of the Kevlar fiber used makes a huge difference in whether it handles bullets or knives. I'm guessing that his designed used a weave intended for knives as it would be more comparable to a bear's claws. That would have to be swapped out.

You know, considering some of the bears you might be facing would be several hundred pounds, and several times stronger than you, maybe you wouldn't want a "bear suit" to be light weight. Just cause their claws and teeth couldn't puncture the suit, doesn't mean they couldn't throw you into trees, pin you to the ground, or knock you into the water. Sometimes weight is a good thing. Unless of course, you are trying to outrun the bear, which you can't do...

Bear to another, so this guy comes over in his lightweight 'bear proof' suit, I tried clawing him - no effect, I tried biting him, no effect, I tried shouting at him, no effect. So I sat on the bugger until he stopped wriggling.

That does require you to inhale them. If they're creating sufficiently long tubes with sufficient durability and weaving them together, it's not as much of a problem. After all, you rarely inhale your shirt.:-) That said, I have no doubt it will be less durable than promised and this will be an issue, but they won't bother with safety tests up front because there are no regulation requiring it yet.